As will be appreciated by those skilled in the art, older lithography techniques for patterning photoresist masks used in etching semiconductor devices can routinely achieve line or area dimensions down to about 0.180 to 0.150 μm. These 0.180 to 0.150 μm features can then be further reduced by etch trimming of the photoresist down to about 0.100 μm. Newer lithography techniques based on lasers with shorter wavelengths can achieve dimensions of about 0.105 μm which can then also be etch trimmed down to about 0.090 to 0.085 μm. Although even more advanced laser techniques may allow further reduction of photoresist dimensions, persons skilled in the art recognize that absent some unexpected laser or etch trimming technology breakthroughs, the dimension or photoresist masking is approaching its theoretical limits.
Therefore, it would be advantageous if a technique other than laser lithography and/or etch trimming can be used to further reduce the line or area dimensions of a photoresist mask. The present invention provides a novel technique that can further reduce photoresist 100 μm line dimensions by an additional 10–20%. Furthermore, the techniques of the present invention can be used to further reduce the line dimensions even after other prior art etch trimming techniques have been employed.